This invention relates to the structure of a card-type processing device such as an IC card and a thin electronic calculator.
An IC card 31 of a conventional type, as shown in FIG. 4 which is its plan view and FIG. 5 which is its sectional view taken along the line 5-5 of FIG. 4, includes a printed circuit board 33 with an LSI chip 32 mounted thereon and a housing 34 which encloses this circuit board 33. The housing 34 is comprised of a lower plate 35 and an upper plate 36 made of vinyl chloride or the like. The LSI chip 32 is electrically connected to the printed circuit board 33 by way of bonding wires 37. On the side of the printed circuit board 33 opposite from the LSI chip 32, there are connecting terminals 38 mounted thereon, exposed to the exterior. These connecting terminals 38 are for making electrical connections to an electronic device such as a portable reader/writer so that data can be exchanged between the IC card 31 and such a device to which it is connected.
To fabricate an IC card structured as described above, the connecting terminals 38 are formed first on the printed circuit board 33 and the LSI chip is then mounted thereonto. The printed circuit board 33, together with the LSI chip 32 mounted thereon, is buried between the lower and upper plates 35 and 36 and their inner surfaces are joined together by a thermal press.
The prior art IC card 31 thus manufactured is uniform throughout its body in material strength. If the user sits down on a chair with such a card in his hip pocket, therefore, a strong local stress is developed and such a stress propagates throughout the card. The LSI chip 2 thereby experiences a bending and/or sharing stress and a severe damage may be sustained.